Add `typst_utils::display`

1 files changed, 20 insertions, 1 deletions

diff --git a/crates/typst-utils/src/lib.rs b/crates/typst-utils/src/lib.rs
index abe6423d..4cfe0c04 100644
--- a/crates/typst-utils/src/lib.rs
+++ b/crates/typst-utils/src/lib.rs
@@ -23,7 +23,7 @@ pub use self::scalar::Scalar;
 #[doc(hidden)]
 pub use once_cell;
 
-use std::fmt::{Debug, Formatter};
+use std::fmt::{Debug, Display, Formatter};
 use std::hash::Hash;
 use std::iter::{Chain, Flatten, Rev};
 use std::num::{NonZeroU32, NonZeroUsize};
@@ -52,6 +52,25 @@ where
     Wrapper(f)
 }
 
+/// Turn a closure into a struct implementing [`Display`].
+pub fn display<F>(f: F) -> impl Display
+where
+    F: Fn(&mut Formatter) -> std::fmt::Result,
+{
+    struct Wrapper<F>(F);
+
+    impl<F> Display for Wrapper<F>
+    where
+        F: Fn(&mut Formatter) -> std::fmt::Result,
+    {
+        fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+            self.0(f)
+        }
+    }
+
+    Wrapper(f)
+}
+
 /// Calculate a 128-bit siphash of a value.
 pub fn hash128<T: Hash + ?Sized>(value: &T) -> u128 {
     let mut state = SipHasher13::new();